I'm having trouble figuring this one out..based on an angular momentum lab.

In the lab we had a turntable with a ball on it, when the ball was released, the intial velocity could be calculated using the formula

[itex]v=d(g/2h)^{1/2}[/itex]

I need to be able to derive the same formula

[itex]v=d(g/2h)^{1/2}[/itex]

using only measureable quantites from my lab.

measure quantities are

height (ball to table top)
mass of the ball
distance between axis of rotation and ball
distance horizontal distance

I have to derive this equation using horizontal and vertical coordinates.

any ideas?

Well, it's motion with constant acceleration. You know how far it fell (vertically) so you should be able to calculate the time it took to fall. Then you know it moved horizontally with constant speed, and you know how far it went and (from the vertical equation) how long it was in the air.